Process Optimization And Simulation For Fine Separation Process Of Fischer-tropsch Oil

Fischer-Tropsch synthesis(FTS)is a synthetic method for producing a large amount of hydrocarbon organics which using syngas as a raw material.Among them,the FTS oil has a short carbon chain and high olefin content under high temperature reaction conditions and iron-based catalyst catalysis.Is a high-quality raw material for separating a-olefin and solvent oil.However,there are few studies on the above separation process in China.The development of separating a-olefins from F-T synthetic oil can not only enhance the value of F-T synthetic oil products,but also make up for the shortage of a-olefin production in China.Therefore,this paper selects three crude products of FTS oil(light hydrocarbon,liquid wax,soft wax)as raw materials and use Aspen Plus as a process simulation tool to optimizate and simulate this fine separation process.Liquid wax and soft wax are used as raw materials for high-purity sol-vent oil,which can be used as a raw material for extracting N-alkanes.The simulation results were verified by the on-site pilot plant.The results show that the experimental results are basically the same as the simulation results and the C10 cut fraction component obtained a qualified single carbon solvent oil.light hydrocarbon are used as raw materials for 99%pure 1-hexene and 98.5%pure 1-pentene after cut by the C5 and C6 fraction.The simulation process of 1-hexene are as follows:remove oxygenates to get hydrocarbon;separation alkene from alkane;Separation of isomeric olefins to get 1-hexene.The simulation process of 1-pentene are as follows:Reactive distillation to remove isomerized olefins with similar boiling points;extractive distillation separation of oxygenates;purification of 1-pentene.The simulation results show that the process in separation of 1-hexene and 1-pentene can achieve the separation target.In order to solve the high energy consumption problem in the 1-hexene separation process,a three-tower extractive distillation process and dividing wall column process are proposed to optimize the above process steps.The results show that the above two processes can achieve the separation target of 99%1-hexene.Results show that the recovery rate of olefins in the three-column extractive distillation process reached 97%and the energy consumption was reduced by 6.0%which was improved compared with the original process.Dividing wall column process simplifies the process,the energy-saving effect is more obvious,and the total heat duty is reduced by 16.5%compared to the original process.The whole process simulation was carried out according to the 1-hexene and 1-pentene process after improved.Finally,1-hexene with 99%purity and 1-pentene with 98.5%purity was obtained and the recovery was 85%and 92%.It is indicated that the above process is feasible and provides theoretical support for the separation of FTS oil.